• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Determining the activation energy of a reaction, By using the experimental data and the Arrhenius equation, the activation energy for the reduction of peroxodisulphate ions, S2O82-(aq) by iodide ions, I-(aq) in a clock reaction is found to be approximatel

Extracts from this document...

Introduction

Determining the activation energy of a reaction Data Collection Table 1: Raw data - time taken for the mixture to turn blue-black in colour Temperature/?�1 30 35 40 45 50 Reaction completion time/second �1 152 99 76 46 44 Data processing Table 2: Processed results from Table 1 Temperature, T /K�1 K-1 Rate constant, K /dm3 mol-1 s-1 ln K 303 0.00330 0.00658 -5.02 308 0.00325 0.0101 -4.60 313 0.00319 0.0132 -4.33 318 0.00314 0.0217 -3.83 323 0.00310 0.0227 -3.78 Note: the rate constant, K is calculated as follows: Graph Note on graph: In this graph T is temperature in Kelvin and t is the time taken for the reaction to reach the blue-black colour stage. A R2 value is calculated in the graph above using Microsoft Excel. The R2 value - or the coefficient of determination, can be an indication of how closely the points relate to a line of best fit. It ranges from 0 to 1 with the latter indicating that the line of best fit can fully predict future points. ...read more.

Middle

However, it is assumed for this investigation that the uncertainty in time is �1 second. Assuming that uncertainties for the Universal Gas Constant, R, and Arrhenius' Constant, A, are zero, and taking the values associated with the median temperature of 313Kelvin we are left with the following limits of accuracies: Time = �1 OR To calculate the uncertainty of ln k, Time for the median temperature, 76 seconds, is taken. Thus, it can be seen that the uncertainty for ln k is approximately �0.01 or 0.231% Calculating the overall uncertainty The Arrhenius equation can be rearranged as follows: Since R and ln A are assumed to have zero uncertainty, the overall uncertainty can be calculated as follows: Uncertainty of T + uncertainty of ln k = 1.32% + 0.231% = 1.55% Overall uncertainty = Therefore, the activation energy is as follows: 52.9kJ mol-1�0.820 Conclusion By using the experimental data and the Arrhenius equation, the activation energy for the reduction of peroxodisulphate ions, S2O82-(aq) ...read more.

Conclusion

A way to improve the accuracy in data collection is to use greater concentrations of solutions so that the change in colour would be more instantaneous. However, for the purpose of this investigation the accuracy of the time recorded was assumed to be approximately �1 second. An improvement that can be made to the method is in the way the solutions are mixed together. In this experiment the two solutions are mixed manually. Although the way in which they were mixed was kept as constant as possible, a better method can be adopted to ensure that all the mixing is done uniformly. For example, a magnetic stirrer can be used in place of manual mixing - one can control the intensity and speed at which the solutions are mixed in this way. One way to develop this experiment further is to investigate in the effect of catalysts such as Fe2+ and Fe3+. Catalysts generally lower the activation energy, so it would be interesting to investigate in how Fe2+ and Fe3+ affect this particular reaction. 1 Eileen Ramsden (2000). A-Level Chemistry. 4th ed. London: Nelson Thornes. 169. ?? ?? ?? ?? Candidate Name: Teng, Eva Yi-Chun Candidate Number: 001407-038 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Chemistry essays

  1. Investigate the rate of reaction of luminol in various factors. The objective was to ...

    250cm3 volumetric flask A volumetric flask is used to make up an accurate and known volume standard solution. Pipette A pipette is used to deliver an accurate volume of a solution, usually 25cm3. It has to be washed with distilled water and the solution once before use.

  2. Limiting Reagent Lab. Purpose To ...

    An example of such substance is KNO3Pb(NO3)2 nitric acid (), which is insoluble to but soluble to. When HNO3Pb(NO3)2KNO3 nitric acid is added to solid and left over (which can be gained KNO3Pb(NO3)2 by boiling the filtrate) only will remain solid; therefore, it can be Pb(NO3)2 filtered to measure the mass.

  1. Lab - Measuring an Activation Energy

    It was quite exciting to watch the reaction for the temperature of about 90�C. Almost immediately after mixing the liquids and starting the stopwatch, the color had completely disappeared - in the blink of an eye. Generally we found that as we increased the temperature of the water baths that

  2. Aim: To calculate the activation energy (EA) for the reaction between Br- and BrO3- ...

    reaction rate = change in concentration/ time = c/t Substituting into the equation: ln K= + ln A Gives us the following equation: ln(c/t) = + ln A Or ln t = +ln e - ln A As both ln c and in ln A are contants, this is the equation of a straight line.

  1. Faraday's Constant

    However, the accepted value for Faraday's Constant is 96,485.34 C mol-1 1. My result is 9.0% lower than the acknowledge value, but this is higher than the percentage error I calculated, so, therefore, my result would not be accepted as accurate.

  2. Determining the Activation Energy of a Reaction

    Reaction Time (s) Average Time (s) Initial Rate of Reaction (mol dm-3 s-1) 275.5 2103.1 - 2103.1 9.50977129 x 10-6 285.5 676.4 710.9 693.65 2.883298493 x 10-5 293.5 362.6 405.4 384.0 5.208333333 x 10-5 306.5 131.3 138.6 134.95 1.482030382 x 10-4 Table 3 - Determining k, ln k, and 1/T Temperature (�K � 0.2� K)

  1. Bomb calorimetry. The goal of this experiment was to use temperature data over ...

    28 20.3 23.2 46 20 22.7 10.5 17.7 19.8 28.5 20.3 23.2 46.5 19.9 22.7 11 17.9 20.1 29 20.3 23.2(Tf) 47 19.9 22.6 11.5 18.1 20.3 29.5 20.3(Tf) 23.2 47.5 19.9 22.6 12 18.3 20.6 30 20.3 23.2 48 19.9 22.6 12.5 18.5 20.8 30.5 20.3 23.2 48.5 19.8

  2. Investigating Factors that Affect the Rate of Reaction of the Decomposition of Hydrogen ...

    Turn on a computer and start the LoggerPro Program. Connect the Gas Pressure Senor to Channel 1of the Vernier computer interface and with the correct cable attach the Vernier computer interface to the computer. Take the plastic tubing with the Leur-lock connectors at either end of the tubing, connect the tubing to the base on the one-hole rubber stopper

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work